My aforementioned U.S. Pat. Nos. 5,000,647 and 5,092,732 present background information with respect to both reciprocating floor conveyors and cargo containers used for transporting goods by ship, truck, and/or railway without unloading the shipped goods from the container at intermediate points. My U.S. Pat. Nos. 5,000,647 and 5,092,732, and U.S. Pat. No. 4,966,275, granted Oct. 30, 1990, to Olof A. Hallstrom, disclose different ways of providing a separable connection between power drive and floor portions of a reciprocating floor conveyor. The floor portion of the conveyor is incorporated into the cargo container. The power drive portion of the conveyor is incorporated into the transporting vehicle for the cargo container.
It is known to mount a conveyor on a conveyor frame and then make the conveyor frame separable from a support frame which carries a drive mechanism for powering the conveyor. A separable connection is provided between the drive mechanism and the conveyor. An early example of this arrangement is disclosed by U.S. Pat. No. 2,401,465, granted Jun. 4, 1946, to John D. Cwicig. This patent discloses an elongated conveyor frame 20 which supports an elongated screw conveyor 23 having a drive sleeve 16. Sleeve 16 includes a square-shaped opening which receives a square drive shaft 12. The drive shaft 12 is a part of a drive mechanism 7 which is carried by a support frame 5. The conveyor frame 20 is mountable on the support frame 5, with the drive shaft 12 extending through the drive sleeve. The engagement of the drive shaft 12 with the drive sleeve provides a detachable connection between the driven component 23 of the conveyor and the drive mechanism 7 carried by the support frame 5. The conveyor is easily and quickly disconnected from the drive mechanism by sliding the drive shaft 12 relatively out from the drive sleeve 16.
A number of years ago, I developed a reciprocating floor conveyor which included detachable connections between hydraulic drive units and transverse drive beams that are connected to the floor members of the conveyor. This enabled a user to disconnect the drive units from the floor members so that the drive units could be separated from the floor portion of the conveyor. Examples of these conveyors are disclosed in my following U.S. Pat. Nos. 4,712,467, granted Dec. 15, 1987; U.S. Pat. No. 4,793,469, granted Dec. 27, 1988; and U.S. Pat. No. 4,821,868, granted Apr. 18, 1989. Each of these conveyors is usable with a cargo container and its transporting vehicle. The drive units are connectable to the main frame members of the vehicle. The transverse drive beams are connectable to floor members in the container. Clamps used to connect the transverse drive beams to the cylinder barrels of the drive units are removable for the purpose of disconnecting the transverse drive beams and the floor members from the drive units.
Early on, I investigated a number of ways of providing a simple plug-in connection which could be used in place of the clamps. These included connections of the type shown in my U.S. Pat. No. 4,899,870, granted Feb. 13, 1990, and in my U.S. Pat. No. 4,907,691, granted Mar. 13, 1990. I considered using a variation of the connection shown in FIGS. 24 and 25 of U.S. Pat. No. 4,899,870. The U-shaped cradle member was directed downwardly and was connected to the bottom of the transverse drive beam. The block was connected to the movable component of the drive unit. The use of a block and cradle member connection was explored because I could see that if I used the detachable clamp-type connection disclosed in my aforementioned U.S. Pat. Nos. 4,712,467, 4,793,469, and 4,821,468, it would be difficult to lower the container onto the support frame and make the connection without structural damage occurring to the drive units. The cargo container is quite large and heavy. A slight sideways movement of it could move the clamp members that are connected to the transverse drive beams against a component of the drive units. Resulting contact could cause substantial damage to the drive units. I soon realized that this problem would exist even if I used a plug-in connection such as the connection disclosed in my U.S. Pat. No. 4,899,870.
An inspection of U.S. Pat. No. 4,966,275 shows that this problem was also recognized by Olof A. Hallstrom. Mr. Hallstrom addresses the problem in a very unique way. He provides two transverse beams for each drive unit. A first transverse drive beam (connector beam) is connected to each set of floor members. A second transverse drive beam (drive member beam) is connected to the moveable component of each drive unit. The connector beam is formed to include a latch socket. The drive member beam is provided with a spring biassed latch pin. In this patent, it is stated (column 3, line 64 to column 4, line 9):
"As the connector beams 34', 40', and 44' are lowered onto the drive member beams 34", 40", and 44", respectively, the latch pins 54, may or may not register with the latch sockets 62, since the drive member beams may be at any random positions relative to the transverse frame. If they do not register, they are depressed into the sleeves 52 against the compressive resistance of the coil springs 60. The drive mechanism then is activated to move the drive member beams 34", 40", and 44" relative to the overlying connector beams 34', 40', and 44', respectively, until the latch pins 54 are brought into registry with latch sockets 62. Thereupon, the latch pins snap into the latch sockets by extension of the coil springs." Prior to learning of this patent, I approached the problem in a much different way, as will hereinafter be described with reference to my aforementioned U.S. Pat. Nos. 5,000,647 and 5,092,732.
It appears to me that the detachable connection disclosed in U.S. Pat. No. 4,966,275 would be undesirable for several reasons. Firstly, if the connector beams should come down onto the drive member beams, with side edges of the connector beams outwardly of the latch pins, and with the connector beams moving sideways toward the latch pins, it would appear that contact between the connector beams and the latch pins would most likely cause severe damage to the latch pins and their support and guide structures. Secondly, it appears that it would be difficult to make the latch pins strong enough to carry the loads that would be imposed on them by the piston-cylinder drive units. Thirdly, it appears that it would be difficult to mount the latch pins in the drive member beams.
Following consideration of a number of separable connections, over a number of years, I approached the problem by providing a drive mechanism characterized by husky drive legs, and by positively lowering the drive legs into a spaced relationship from all parts of the container, and maintaining this spaced relationship until the container is fully loaded onto, and is securely connected to, the transporting vehicle. I then positively raised the drive legs upwardly to place their upper ends into sockets in the transverse drive beams to make the drive connection. As disclosed in my U.S. Pat. Nos. 5,000,647 and 5,092,732, the drive legs are at their lower ends mounted for pivotal movement on vertically movable supports. A separate piston-cylinder drive unit is connected to each drive leg. Extension and retraction of the drive units swing the drive legs in position about their lower ends and reciprocate the slat members. The drive legs are raised and lowered by pneumatic lifts which also allow the drive legs to move downwardly as they swing so that the upper ends of the drive legs travel straight rather than arcuate paths.
Experimentation with the conveyor system disclosed in my U. S. Pat. Nos. 5,000,647 and 5,092,732 led to the making of the present invention. An object of the present invention is to provide an improved apparatus for vertically moving the drive legs. Another object of the invention is to provide each drive leg (herein "drive post") with a pair of piston-cylinder units which are adapted to help hold the drive posts in a driving engagement with the transverse drive beams. A further object of the invention is to provide a mechanism for guiding and bracing the transverse drive beams as they are reciprocated. This feature of the invention has general utility with respect to all types of reciprocating slat conveyors.